GM Service Manual Online
For 1990-2009 cars only

Circuit Description

An secondary air injection (AIR) pump is used on this vehicle to lower tail pipe emissions at start-up. The powertrain control module (PCM) supplies a ground to the AIR pump relay, which energizes the AIR pump and the AIR solenoid.

When the AIR pump is enabled, the PCM monitors the heated oxygen sensor (HO2S) voltage. If the HO2S voltages go below a calibrated threshold value, the PCM interprets this as an indication that the AIR system is operational.

When the AIR pump is disabled, the PCM monitors the HO2S voltages. The HO2S voltages should increase above a calibrated threshold value and switch normally.

If the PCM did not sense more than a predetermined amount of HO2S rich switches, a malfunction will be reported.

The PCM will activate the AIR pump during Closed Loop operation. When the AIR system is activated, the PCM will monitor the HO2S voltages and short term fuel trim values for both banks of the engine. If the AIR system is operating properly, the HO2S voltages should go low and the short term fuel trim should go high.

The PCM checks that the HO2S voltages return to above a rich threshold when the AIR pump is disabled.

If the PCM determines that the HO2S voltages for both banks did not respond as expected during the tests, DTC P0410 will set. If only one sensor responded, the PCM will set either a DTC P1415 or P1416 to indicate on which bank the AIR system is inoperative.

Conditions for Running the DTC

    • DTCs P0116, P0137, P0138, P0140, P0141, P0143, P0144, P0146, P0147, P0151-P0155, P0157, P0158, P0160, P0161, P0171, P0172, P0174, P0175, P0300, P0500, P1106, P1107, P1111, P1112, P1114, P1115, P1121, P1122, P1133, P1134, P1153, P1154, P1351, or P1361 are not set.
    • The mass air flow (MAF) is less than 22 g/s.
    • The engine load is less than 33.25 percent.
    • The power enrichment mode is not active.
    • The decel fuel cutoff (DFCO) mode is not active.
    • The converter over temperature is not active.
    • The engine run time after Closed Loop is more than 20 seconds.
    • The air/fuel ratio is 13.125:1.
    • The short term fuel trim is between -3 and +3 percent.
    • The engine speed is above 900 RPM.
    • The engine coolant temperature (ECT) is between 70-110°C (158-230°F) .
    • The system voltage is more than 11.7 volts.
    • The intake air temperature (IAT) is between 2-100°C (36-212°F).
    • The vehicle speed is more than 15 km/h (25 mph).

Conditions for Setting the DTC

The HO2S voltage is more than 222 mV for more than 1 second when the AIR pump is commanded ON by the control module.

Action Taken When the DTC Sets

    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

A low AIR system volume may cause a DTC P1415, P1416, or an intermittent complaint. Also check for the following conditions:

    • Pinched, kinked, or restricted AIR pipes, hoses or fittings
    • Leaks, holes, and loose fittings or hoses
    • A restricted or obstructed AIR pump inlet, duct or filter
    • Leaks or restrictions in the vacuum hoses for the AIR shut-off valve

An AIR supply hose that is melted before the check valve may indicate exhaust gas back-flow past the check valve.

An intermittent may be caused by any of the following conditions:

    • Moisture, water, or debris ingestion into AIR pump
    • Excessive exhaust system back pressure

Thoroughly inspect any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step will determine if the AIR system is functioning correctly.

  2. The engine must be running for this test to ensure a vacuum supply to the system.

  3. This step will determine if the AIR pump is capable of producing airflow.

  4. This step will determine if the PCM is capable of controlling the AIR pump relay.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Inspect the AIR maxifuse.

Is the fuse open?

--

Go to Step 13

Go to Step 3

3

Inspect the ignition 1 fuse.

Is the fuse open?

--

Go to Step 29

Go to Step 4

4

  1. Install the scan tool.
  2. Start the engine and allow the engine to run for 2 minutes.
  3. Verify the engine is running at normal operating temperature and is in Closed Loop.
  4. Command the AIR pump ON with a scan tool.

Does the short term FT indicate a change of more than the specified value within 30 seconds?

20%

Go to Step 5

Go to Step 6

5

The DTC is intermittent.

Are any additional DTCs stored?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Diagnostic Aids

6

  1. Turn ON the ignition, with the engine OFF.
  2. Command the AIR pump relay ON with a scan tool.

Does the AIR pump turn ON?

--

Go to Step 7

Go to Step 9

7

Command the AIR pump relay OFF with a scan tool.

Does the AIR pump turn OFF?

--

Go to Step 16

Go to Step 8

8

  1. Turn OFF the ignition.
  2. Remove the AIR pump relay.
  3. Turn ON the ignition, with the engine OFF.

Does the AIR pump turn ON?

--

Go to Step 34

Go to Step 9

9

  1. Turn OFF the ignition.
  2. Disconnect the AIR pump relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the AIR pump relay battery positive supply terminal at the relay connector with a test lamp connected to ground. Refer to Using Connector Test Adapters in Wiring Systems.

Is the test lamp illuminated?

--

Go to Step 10

Go to Step 31

10

Jumper the battery positive terminal to the AIR pump feed circuit at the relay harnesses connector using a fused jumper. Refer to Using Fused Jumper Wires in Wiring Systems.

Does the AIR pump illuminate?

--

Go to Step 22

Go to Step 11

11

  1. Leave the jumper installed.
  2. Disconnect the AIR pump electrical connector.
  3. Probe terminal A of the AIR pump electrical connector with a test lamp connected to ground. Refer to Using Connector Test Adapters in Wiring Systems.

Does the lamp illuminate?

--

Go to Step 12

Go to Step 33

12

  1. Leave the jumper installed.
  2. Connect a test lamp from terminal A to terminal B of the AIR pump harness connector.

Does the test lamp illuminate?

--

Go to Step 37

Go to Step 39

13

  1. Turn OFF the ignition.
  2. Remove the AIR relay.
  3. Remove the AIR maxifuse.
  4. Probe the battery feed terminal at the AIR pump relay harness connector with a test lamp connected to battery positive. Refer to Using Connector Test Adapters in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 32

Go to Step 14

14

  1. Disconnect the electrical connector from the AIR pump and the AIR solenoid.
  2. Probe the AIR pump/AIR solenoid feed circuit at the AIR pump relay harness connector with a test lamp connected to battery positive. Refer to Using Connector Test Adapters in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 35

Go to Step 15

15

  1. Reinstall the following components/electrical connector:
  2. • A new AIR maxifuse
    • The AIR pump relay
    • The AIR pump solenoid
  3. Turn ON the ignition, with the engine OFF.
  4. Command the AIR pump relay ON with a scan tool.

Does the AIR maxifuse open?

--

Go to Step 45

Go to Step 30

16

  1. Turn OFF the ignition.
  2. Disconnect the AIR solenoid harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the terminal for the solenoid battery positive voltage circuit at the AIR solenoid harness connector with a test lamp connected to a ground.
  5. Command the AIR pump relay ON with a scan tool.

Does the test lamp illuminate?

--

Go to Step 17

Go to Step 33

17

  1. Connect a test lamp between terminal A and terminal B of the AIR solenoid valve harness connector
  2. Command the AIR pump relay ON with a scan tool.

Does the test lamp illuminate?

--

Go to Step 18

Go to Step 37

18

  1. Disconnect the vacuum harness from the AIR solenoid.
  2. Connect a vacuum gage to the vacuum source hose.
  3. Start the engine.

Is the reading on the gage more than the specified value?

12 in Hg

Go to Step 19

Go to Step 38

19

  1. Reconnect only the vacuum supply hose to the AIR solenoid.
  2. Connect a vacuum gage to the other port of the AIR solenoid.
  3. Command the AIR pump relay ON with a scan tool with the engine running.

Is the reading on the gauge more than the specified value?

12 in Hg

Go to Step 20

Go to Step 45

20

  1. Reconnect the vacuum hose to the AIR solenoid.
  2. Disconnect the AIR shut-off valve inlet hose at the AIR shut-off valve.
  3. Start the engine.
  4. Command the AIR pump relay ON with a scan tool.

Is air flow present at the AIR shut-off valve inlet hose?

--

Go to Step 21

Go to Step 37

21

  1. Reconnect the AIR inlet hose to the AIR shut-off valve.
  2. Disconnect the AIR shut off valve output hose at the AIR shut-off valve.
  3. Start the engine.
  4. Command ON the AIR pump with the scan tool.

Does air flow from the AIR shut-off valve?

--

Go to Step 28

Go to Step 40

22

  1. Turn ON the ignition.
  2. Probe the ignition 1 voltage circuit terminal at the AIR pump relay with a test lamp connected to a good ground

Does the test lamp illuminate?

--

Go to Step 23

Go to Step 31

23

  1. Probe the air pump relay control circuit at the relay terminal with a test lamp connected to battery positive.
  2. Command the AIR pump relay ON with a scan tool.

Does the test lamp illuminate?

--

Go to Step 24

Go to Step 25

24

  1. Probe the air pump relay control circuit at the relay terminal with a test lamp connected to battery positive.
  2. Command the AIR pump relay OFF with a scan tool.

Does the test lamp turn OFF?

--

Go to Step 36

Go to Step 27

25

  1. Disconnect the connectors from the PCM.
  2. Probe the control circuit at the relay connector with a test lamp connected to a good ground.

Does the test lamp illuminate?

--

Go to Step 42

Go to Step 26

26

  1. Remove the AIR pump relay.
  2. Measure the resistance of the AIR pump relay control circuit between the AIR relay and the control module connector with a DMM for an open. Refer to Testing for Intermittent Conditions and Poor Connections and Testing for Continuity in Wiring Systems.

Is the reading within specifications?

0-5 ohms

Go to Step 46

Go to Step 41

27

  1. Disconnect the PCM connectors.
  2. Test the air pump relay control circuit between the control module and the AIR pump relay for a short to ground.

Did you find a problem?

--

Go to Step 43

Go to Step 46

28

Check for leaks or restrictions in the following components:

    • Hoses
    • Check valves
    • Fittings
    • AIR pipes
    • Exhaust manifolds

Did you find a problem?

--

Go to Step 44

Go to Diagnostic Aids

29

  1. Turn ON the ignition.
  2. Probe the ignition 1 voltage circuit terminal at the AIR pump relay connector with a test lamp connected to battery positive.

Does the test lamp illuminate?

--

Go to Step 32

Go to Diagnostic Aids

30

  1. Reconnect the AIR pump.
  2. With a scan tool, command the AIR pump ON.

Does the AIR maxifuse open?

 

Go to Step 37

Go to Diagnostic Aids

31

Repair the open in the circuit between the fuse and the relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 48

--

32

Repair the short to ground in the circuit between the fuse and the relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 48

Go to Step 35

33

Repair the open in the circuit between the relay and the AIR pump/solenoid. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 48

--

34

Repair the short to voltage in the circuit between the relay and the AIR pump/solenoid. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 48

--

35

Repair the short to ground between the AIR relay and the AIR pump/solenoid. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 48

--

36

Replace the AIR pump relay.

Did you complete the replacement?

--

Go to Step 48

--

37

Replace the AIR pump. Refer to Secondary Air Injection Pump Replacement .

Did you complete the replacement?

--

Go to Step 48

--

38

Repair the leak or restriction in the vacuum hose.

Did you complete the repair?

--

Go to Step 48

--

39

Repair the open in the AIR pump ground circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 48

--

40

Replace the AIR shut-off valve. Refer to Secondary Air Injection Shutoff Valve Replacement .

Did you complete the replacement?

--

Go to Step 48

--

41

Repair the open in the AIR relay control circuit between the relay and the PCM. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 48

--

42

Repair the short to voltage in the AIR relay control circuit between the relay and the PCM. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 48

--

43

Repair the short to ground in the AIR relay control circuit between the relay and the PCM. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 48

--

44

Repair the air delivery system as necessary.

Did you complete the repair?

--

Go to Step 48

--

45

Replace the AIR pump solenoid. Refer to Secondary Air Injection Vacuum Control Solenoid Valve Replacement .

Did you complete the replacement?

--

Go to Step 48

--

46

  1. Check the PCM connections.
  2. Repair as necessary.

Was a repair necessary?

--

Go to Step 48

Go to Step 47

47

Replace the PCM. Refer to Powertrain Control Module Replacement and Powertrain Control Module Programming .

Did you complete the replacement?

--

Go to Step 48

--

48

  1. Install the scan tool.
  2. Start the engine and allow it to run for 2 minutes.
  3. Verify the engine is running at normal operating temperature and is in Closed Loop.
  4. Command ON the AIR pump with the scan tool.

Does the short term FT indicate a change of more than the specified value within 30 seconds?

20%

Go to Step 49

Go to Step 6

49

  1. Using the scan tool, clear the DTCs.
  2. Turn OFF the engine for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

--

Go to Step 50

Go to Step 6

50

With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK